You can implement soundscapes easily. Not in the engine, of course, since we have no access to the engine itself, but rather in the game library.
Take a look at how a simple entity class is written, like func_wall.
The problem with emitting sounds programmatically is that you cannot tell the engine
where to play the sound from. Instead the sound is always emitted from an entity's centre. You can spawn a dummy entity that will follow the player and whatnot, and then emit sounds randomly from that one.
Now, there are a few more additions that can be made, like 2D sounds, which requires the use of so-called user messages (basically server-to-client messages).
"It really helped me out sometimes."
Someone actually USES that?! LOL